Honeybees are self-sufficient, but beekeepers can help keep their honeybees alive during the fluctuating temperatures of winter. / Courtesy of Charleen Barr

Written by

Charleen Barr

CSU Master Gardener

Larimer County Extension

Larimer County is a county-based outreach of Colorado State University Extension providing information you can trust to deal with current issues in agriculture, horticulture, nutrition and food safety, 4-H, small acreage, money management and parenting. For more information about CSU Extension, Larimer County, telephone (970) 498-6000 or visit www.larimer.org/extPlantTalk Colorado

Visit PlantTalk Colorado for fast answers to your gardening questions: www.planttalk.org PlantTalk is a cooperation between Colorado State University Extension, GreenCo and Denver Botanic Gardens. PlantTalk is also on Youtube!

More

ADVERTISEMENT

As fall lingers and temperatures drop, insects go through an abrupt change in lifestyle. Their activity and development largely ceases, but they have strategies to survive winter.

Insects’ worst enemies are the alternating extremes of very cold and very warm weather that can come during winter months.

Honeybees remain in their hives through the winter but do not hibernate. Maintaining the hive is a constant job in warm weather and cold. They have spent the spring and summer creating food to sustain the hive and raise a new brood in the form of nectar and pollen. Their constant activity takes a toll; an individual bee may live only four to six weeks in the summer.

Honeybees do not forage in temperatures that dip below 50 degrees; instead, the bees remain in the hive and work hard to keep the queen and any brood warm. Honeybees maintain a year-round hive temperature of 90 degrees. In addition, there is less risk involved while remaining in the hive so overwintering honeybees will live for several months.

They have one of nature’s perfect examples of insect “communal living.” Their metabolic rate remains normal as they cluster together to maintain the hive temperature. Worker bees will create a cluster, flexing their wing muscles to generate heat. The ball is constantly moving as the bees on the outermost edge of the cluster move inward to warm themselves; those on the inside move out. They remain over the queen and brood to keep them from becoming chilled and dying. Honeybees also move to areas of honey stores in order to eat.

Other insects that enjoy communal living include ants and termites who head below frost line, where their large numbers and stored food keep them comfortable until spring arrives.

Many insects “migrate” by heading to warmer climates or better conditions as winter approaches. One of the most famous migrating insect is the monarch butterfly that will fly up to 1,000 miles to spend winters in Mexico. Many butterflies and moths migrate seasonally, including the gulf fritillary, the painted lady, the black cutworm and fall armyworm. Dragonflies that live near ponds and lakes as far north as Canada will also migrate.

(Page 2 of 2)

Insects that live in higher altitudes or near the Earth’s poles use a state of “torpor” to survive drops in temperature. Torpor is a temporary state of suspension or sleep, during which the insect is completely immobile. Along the Front Range, we do not have insects that survive using torpor.

Diapause is a long-term state of suspension. Diapause synchronizes the insect’s life cycle with seasonal changes in its environment, including winter conditions. Insect diapause may occur in any state of insect development, such as eggs: praying mantids survive the winter as eggs, which emerge in spring. Larvae such as woolly bear caterpillars curl up in thick layers of leaf litter for winter; in the spring they spin their cocoons. Black swallowtails pupate spending winter as chrysalids, emerging as butterflies when warm weather comes. Some adult insects such as lady beetles and mourning cloak butterflies move to winter quarters, under plant debris, behind bark flaps or walls of homes. During this period (which may last six months or more) their development is temporarily suspended,

As winter approaches, some larva, pupa, and adult insects produce glycerol in their cells that prepares them for the cold by making their own antifreeze. Larvae of mountain pine beetle are able to survive the winter by metabolizing glycerol. During the fall, insects produce glycerol that gives the insect body “super cooling” ability, allowing insect fluids to drop below freezing without causing ice damage.

Whether looking forward to the pollinators and beneficials or dreading the resuming of pest battles, rest assured, after the winter thaws, they will all be back. For more information, visit www.planttalk.org and read Planttalk script #1440 on “Insect Overwintering.”

Charleen Barr has received training through Colorado State University Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.